2. Pilot study-Despite stronger evidence for chlorthalidone, most hypertensive patients prescribed diuretics currently receive HCTZ. However, the two have not been randomly compared in an adequately powered study. The investigators will require 80 newly hypertensive urban subjects to detect a greater than 5mmHg mean automated BP difference between the two groups over 2 monthly follow-up visits (8 weeks total, with a standardized effect size of 0.7 based on prior data). The investigators will include ethnic and under-served subjects. Exclusion criteria will include compelling indications for alternative anti-hypertensives. Non-blinded random allocation will be generated online.